Patent Application
20100223730
Embodiments of the present invention relate to cushions used to cushion at least a portion of a body of a person, the body of an animal, or other thing and to methods of making and using such cushions.
Cushions for cushioning at least a portion of a body of a person, the body of an animal, or other thing are fabricated in a wide variety of configurations and using a wide variety of materials. For example, polymeric foams are often used to form cushions. Cushions have also been fabricated using what are referred to in the art as “gelatinous elastomeric materials,” “gel elastomers,” “gel materials,” or simply “gels.” These terms are used synonymously herein, and mean a plasticized elastomeric polymer composition comprising at least 15% plasticizer by weight, having a hardness that is softer than about 50 on the Share A scale of durometer, and a tensile elongation at failure of at least about 500%. Such gels, methods for making such gels, and applications in which such gels may be used are disclosed in, for example, U.S. Pat. No. 5,749,111, which issued May 12, 1998 to Pearce, U.S. Pat. No. 5,994,450, which issued Nov. 30, 1999 to Pearce, and in U.S. Pat. No. 6,026,527, which issued Feb. 22, 2000 to Pearce, each of which patents is incorporated herein in its entirety by this reference.
In some embodiments, the present invention includes cushions that comprise a plurality of core structures. Each core structure of the plurality of core structures comprises a deformable polymer material, and is configured as a column having a column axis. Each core structure of the plurality of core structures is interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures. Each core structure may be interconnected to at least one other core structure by a joiner rib.
In additional embodiments, the present invention includes cushions that comprise a plurality of core structures. Each core structure of the plurality of core structures comprises a gel material and is configured as a column having a column axis. Each core structure of the plurality of core structures is interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures by at least one joiner rib. Each core structure of the plurality of core structures is configured to buckle when compressed along the column axis of the core structure to a pressure beyond a threshold pressure level.
In further embodiments, the present invention includes methods of forming cushions that comprise forming a plurality of core structures each comprising a deformable polymer material and configured as a column having a column axis. Each core structure of the plurality of core structures is configured to be interconnected along a length thereof to at least one other core structure of the plurality of core structures by a joiner rib.
The illustrations presented herein are not actual views of any particular cushion, or feature thereof, but are merely idealized representations which are employed to describe embodiments of the invention.
As discussed in further detail below, each of the core structures 102 may comprise an individual hollow or solid structure that is laterally connected to at least one other of the core structures 102. A joiner rib 120 may be used to connect the core structures 120. Furthermore, each of the core structures 102 may comprise a gel, as discussed in further detail below.
As shown in
The core structures 102 may have any hollow or solid cross-sectional shape at any plane orthogonal to the intended principle cushioning direction such as circular, square, rectangular, triangular, star-shaped, hexagonal, octagonal, pentagonal, oval, I-beam, H-beam, E-beam, or irregular shaped. The core structures 102 can be of any shape, and do not need to have a uniform cross-sectional shape along the length of the core structures 102. For example, the top ends 110 of the core structures 102 may have a square cross-sectional shape, the bottom ends 112 of the core structures 102 may have an oval cross-sectional shape, and the cross-sectional shape of the core structures 102 may transition from the square shape to the oval shape along the length of the core structures 102. In some embodiments, the core structures 102 may have varying average diameters along the lengths of the core structures 102. In embodiments in which the core structures 102 are hollow, the wall thicknesses of the core structures 102 may vary along the lengths of the core structures 102. Furthermore, in some embodiments, the core structures 102 may have a material composition that varies along the lengths of the core structures 102.
In the same cushion 100, one or more core structures 102 may be different from one or more other core structures 102 of the cushion in shape, size, material composition, etc. The spacing between core structures 102 in a cushion 100 may be uniform, or it may vary within the cushion 100. The outer lateral side surfaces of the core structures 102 may be vertically oriented, or they may be oriented at an acute angle other than zero degrees) (0°) to vertical, and the angle may vary (continuously or in a step-wise manner) along the length of the core structures 102.
The core structures 102 are shown as having uniform lengths or heights (i.e., the dimension extending along the column axis L102 of the core structures 102), but they can have varying heights in additional embodiments. Such configurations may be desirable in cushions where a top cushioning surface having a contour may be desirable, such as, for example, in wheelchair cushions.
As non-limiting examples, each core structure 102 may comprise a wall 114 having an average thickness of between about one tenth of a centimeter (0.1 cm) and about twenty-five centimeters (25 cm). Furthermore, each core structure 102 may have an average outer diameter of between about one half of a centimeter (0.5 cm) and about twelve centimeters (12 cm). The core structures 102 may have a length (i.e., a height) of between about one half of a centimeter (0.5 cm) and about thirty centimeters (30 cm). The shortest distance between the outer walls 114 of adjacent core structures 102 may be between about zero centimeters (i.e, touching but not connected) and about fifteen centimeters (15 cm).
Individual core structures 102 may be configured to buckle when compressed in the intended cushioning direction (e.g., in a direction at least substantially parallel to the column axis L102 of the core structures 102) beyond a threshold load. Furthermore, individual core structures 102 may be configured to deform when sheared in a direction transverse to the intended principle cushioning direction (e.g., in a direction generally perpendicular to the column axis L102) to allow relative transverse movement between the top ends 110 and the bottom ends 112 of the core structures 102.
Continuing to refer to
The joiner ribs 120 may have any shape and size, and may extend vertically from the top ends 110 to the bottom ends 112 of the core structures 102 along an entire length of the core structures, or they may extend only along a portion of the length of the core structures 102. The joiner ribs 120 may be located on a surface of the core structures 102 anywhere along the length of the core structures 120. In some embodiments the joiner ribs 120 may be located at about a midpoint along the length of the core structures 102. In other words, the distance from the top ends 110 of the core structures 102 to the joiner ribs 120 is about equal to the distance from the bottom ends 112 of the core structures 102 to the joiner ribs 120. In additional embodiments, the joiner ribs 120 may be located at about twenty percent, forty percent, or seventy-five percent of the length of the core structure 102 from the top end 110 of the core structure 102.
The joiner ribs 120 may have a length (i.e., the dimension that is parallel to the axes L102 of the core structures 102) that is less than the length of the core structures 102 as shown in
In some embodiments, as shown in
In additional embodiments, as shown in
The joiner ribs 120 may be used to maintain the desired spacing between the core members 102 within the cushion 100. For example, in some embodiments, it may be desirable to maintain uniform spacing of the core members 102 within the cushion. The core members 102 may shift or move under load from a cushioned object. When the cushioned object is removed and the core members return to their original shape, the joiner ribs 120 help maintain the core members 102 in their desired spacing.
In some embodiments, the core structures 102, and optionally the joiner ribs 120, may comprise a gel. The core structures 102 may be formed entirely from a gel, or they may have a composition comprising a gel and one or more additional non-gel materials. The core structures 102 may be bare, un-coated core structures 102, or they may be coated or covered with or fused to another material. The core structures 102 may have a composition and configuration selected to cause the core structures 102 to be structurally stable so as to stay oriented toward the intended cushioning direction when not under load from a cushioned object. The joiner ribs 120 may be used to maintain desirable spacing between the core structures 102 (including, if desired, to maintain them in physical contact with one another). The area surrounding the core structures 102 may be void, or the core structures 102 may be surrounded by another material, such as a supporting material. Such materials are described in detail in, for example, U.S. patent application Ser. No. ______ (Attorney Docket No. 3388-9982.3), which was filed on May 20, 2010 and entitled “Cushions Comprising Core Structures and Related Methods,” the entire disclosure of which is incorporated herein by this reference. For example, the core structures 102 may be surrounded by a supporting material (not shown) comprising a foam material.
In some embodiments, as shown in
The use a connecting layer 104, 105 is optional. If a connecting layer 104, 105 is used at one end of the core structures 102 or at any point along the length of the core structures 102, a second connecting layer 104, 105 is not required to be used (but may be used) at the opposite end of the core structures 102 or at any other point along the length of the core structures 102. For example, only the top connecting layer 104 or the bottom connecting layer 105 may be used. The use of a single connecting layer 104, 105 may be advantageous for some configurations of core structures 102. For example, a hollow, cylindrical core structure 102 of gel that is about five centimeters (5 cm.) in diameter, about five centimeters (5 cm.) in height, and has a wall thickness of about twenty-five hundredths of a centimeter (0.25 cm.), and that is not filled with foam or any other support material, may collapse or deform under a compressive load while cushioning, and may not return their proper orientation and configuration after release of the compressive load. Bonding at least one of the top ends 110 of such core structures 102, the bottom ends 112 of such core structures 102, or any other point along such core structures 102 to a connecting layer 104, 105 may assist in preventing such occurrences.
In some embodiments, the core structures 102 may be configured to individually or collectively buckle at a threshold compressive load. If the core structures 102 are designed to buckle, the buckling causes the load vs. deflection (i.e., stress vs. strain) curve to be non-linear. In other words, a plot of the stress as a function of strain will deviate from a straight elastic line, as shown by the non-limiting examples of load vs. deflection curves for buckling core structures 102 shown in
The pressure acting on the cushioned object may also be reduced because buckling of the core structures 102 allows the cushion 100 to conform to the shape of the cushioned object, which may result in an increase in the surface area of the cushioned object over which the pressure is applied. Since pressure is load divided by surface area, increasing the surface area over which the load is applied lowers the pressure acting on the cushioned object.
As one non-limiting example, the cushion 100 may comprise a mattress for a bed that is configured to support the entire body of a person or animal (such as a dog or cat) thereon. In such an embodiment, a plurality of core structures 102 may be arranged as lines with joiner ribs 120 connecting the core structures in each line, as shown in
As previously discussed, the composition and configuration of the core structures 102 may be selected to allow the top ends 110 of the core structures 102 to move laterally relative to the bottom ends 112 of the core members 102 when a shear stress is applied to the cushion 100. Such shear stresses may be relieved by the relatively easy lateral movement of the top of the cushion relative to the bottom of the cushion. In addition, the joiner ribs 120 may be configured to not substantively interfere with the movement of the top ends 110 of the core structures 102 laterally relative to the bottom ends 112 of the core members 102 when a shear stress is applied to the cushion 100.
Energy is required to cause a core member 102 to buckle and to return to an unbuckled configuration. Thus, the absorption of energy by the cushioning members 102 while buckling and returning to an unbuckled configuration results in absorption of shocks and attenuation of vibrations by the cushion. It also takes energy to compress or elongate the material of the core structures 102 (even in the absence of buckling). Thus, the composition of the core structures 102 may be selected to comprise a material that is relatively efficient in absorbing shocks and attenuating vibrations to help the cushion 100 absorb shocks and attenuate vibrations. For example, elastomeric gels are relatively efficient in absorbing shocks and attenuating vibrations.
Thus, embodiments of cushions 100 of the invention may provide improved equalization and/or redistribution of pressure, shear relief, and/or shock absorption and/or vibration attenuation, when compared to at least some previously known cushions. In addition, when the core structures 102 are configured to buckle at a threshold buckling load, the cushions may further provide support and alignment. For example, in a mattress, the core structures 102 under the most protruding body parts (e.g., hips and shoulders) can buckle, while the core structures 102 under the least protruding body parts hold firm without buckling (although they may compress due to a load thereon that is below the buckling threshold load). The torso of the supported body is supported, while the spine and back of the supported body is maintained in alignment (all while eliminating high pressure points on the hips and shoulders, or other protruding areas). If the hips and shoulders were not allowed to sink in, the torso would not be sufficiently supported, and the torso and, hence, the spine would have to bend to contact and be supported by the mattress. Thus, a mattress comprising core structures 102 in a support material 104 as disclosed herein may result in a reduction in excessive pressure points on a body supported by the mattress or other cushion, and may improve the alignment of the spine of the body of a person sleeping on the mattress. The result may be less tossing and turning, and less likelihood of back or neck pain.
The core structure shown in
The direction from which a cushioned object will approach and impinge on the cushion 100 may be considered when designing embodiments of cushions of the invention. Some cushions need to provide cushioning in any of several directions (for example, in a number of differing degrees away from a principle cushioning direction, such as ten degrees away, twenty degrees away, and/or thirty degrees away), and the shapes and orientations of the various core structures 102 may be designed such that the cushion will provide a desirable cushioning effect along all such expected cushioning directions. In many embodiments of cushions, however, it is generally known that the cushioning direction will be at least primarily along a principle cushioning direction. For example, gravity will drive a person sitting on a flat horizontal seat cushion, laying on a flat horizontal mattress cushion, or standing on a relatively flat horizontal shoe sole cushion, into the cushion in a direction generally orthogonal to the major top cushioning surface of the cushion. If, for example, the core structures 102 of
The cushion 100 may be designed to cause the core structures 102 to individually or collectively buckle only under the higher pressure points (usually the most protruding areas) and be supported by the other areas without buckling by selecting particular combinations of the several variables affecting the threshold buckling load, which include the spacing between the core structures, the stiffness (i.e., elastic modulus) of the material of the core structures 102, the diameter of the core structures 102, the height (i.e., length along the axis L102) of the core structures 102, the thickness of the wall 114 of the core structures 102, the durometer (i.e., hardness) of the material or materials from which the core structures 102 are made, the expected weight of a body to be supported on, and cushioned by, the cushion 100, the expected surface area of the supported body in contact with the cushion 100, the shape, dimensions, and locations of the support material 104, the stiffness of the support material 104, the durometer of the support material 104, etc. Test data and practical testing and experience will allow various combinations of such variables to be selected so as to provide desirable threshold buckling loads and other cushioning characteristics of the cushion 100 (e.g., displacement at buckling, etc.). Of course, cost is also an important consideration, and the cushioning characteristics of the cushion 100 may not be optimized from a performance perspective in favor of lowering the cost of the cushion 100 to consumers. For example, elastomeric gels are generally more expensive than polymeric foams, and, thus, it may be desirable to employ less gel to lower the cost of the cushion 100 than would otherwise be desirable if cushioning characteristics were to be optimized. For example, a foam border around the periphery of a sofa cushion could be employed so that the core structures 102 need only be used under the coccyx and ischial tuberosity bones of the sitting user, or similarly a foam border can be used around the periphery of a mattress core comprising such core structures 102.
As shown in
In additional embodiments, the bottom ends 112 of the core structures 102 may be heat-fused to a cotton tricot one-way stretch fabric of the bottom layer 108. Another such fabric of the top layer 106 may be heat-fused to the top ends 110 of the core structures 102. If the top layer 106 and the bottom layer 108 further include a layer of foam, such layers of foam also may be glued or otherwise adhered over the top connecting layer 104 and the bottom connecting layer 105.
Another embodiment of a cushion 200 of the invention is shown in
Referring to
The joiner ribs 120, when used in conjunction with a screed mold manufacturing process (as discussed in further detail below), may allow multiple core structures 102 to be progressively pulled out from a mold without the need of having a skin on the top of the mold. The joiner ribs 120 may also allow multiple core structures 102 to be placed into one or more fixtures preparatory to bonding (e.g., heat fusing) a material (e.g., fabric) to the top ends 110 and/or the bottom ends 112 of the core structures 102. Optionally, the joiner ribs 120 may be severed and/or completely removed from the core structures 102 before use of the core structures 102 in a cushion 100. In such instances, the advantage of easy removal of the core structures 102 from a mold may be utilized, and the presence of severed joiner ribs 120 on the core structures 102 may have little or no affect on the cushioning characteristics of the cushion 100.
A non-limiting example embodiment of a mattress comprising core structures 102 like those illustrated in
Layer 1: A fifteen centimeter (15 cm.) (about six inches) thick layer of conventional polyurethane foam having an indentation load deflection (ILD) rating of twenty seven (27 ILD) and a density of about 0.03 g/cm3 (about 1.8 lb/ft3), which is commercially available from FXI Foamex Innovations of Media, Pa. This layer, in combination with Layers 2 and 3 as described below corresponds to the bottom layer 108 of
Layer 2: A water-based adhesive commercially available under the product name SIMALFA® 309 from Alfa Adhesives, Inc. of Hawthorne, N.J., which is used to bond Layer 1 to Layer 3.
Layer 3: Cotton tricot, stretchable in at least one direction available from Culp, Inc. of High Point, N.C. in a number of fabric weights.
Layer 4: A layer including hollow, cylindrical gel core structures (with joiner ribs in one direction as described herein with reference to
Layer 5: Cotton tricot, stretchable in at least one direction available from Culp, Inc. of High Point, N.C. in a number of fabric weights.
Layer 6: A water-based adhesive commercially available under the product name SIMALFA® 309 from Alfa Adhesives, Inc. of Hawthorne, N.J.
Layer 7: A two and a half centimeters (2.5 cm) (about one inch) thick layer of 19 ILD TALALAY latex foam rubber commercially available from Latex International of Shelton, Conn. This layer, in combination with the Layer 5 cotton tricot fabric connecting layer and the adhesive of Layer 6, corresponds to the top layer 106 of
Cover: A standard quilted cover as well known in the mattress industry. Alternatively, a non-quilted stretch cover such as is common for memory foam beds such as TEMPUR-PEDIC® brand memory foam beds sold by Tempur-Pedic, Inc. of Lexington, Ky.
Another non-limiting example embodiment of a mattress comprising core structures 102 like those illustrated in
Layer 1: A fully foam-encased layer of pocketed (jacketed with film or fabric) metal coil springs of the type that is well known in the mattress industry. This layer may have a thickness of about twelve and seven tenths of a centimeter (12.7) (about eight inches).
Layer 2: A water-based adhesive commercially available under the product name SIMALFA® 309 from Alfa Adhesives, Inc. of Hawthorne, N.J., which is used to bond Layer 1 to Layer 3.
Layer 3: Cotton tricot, stretchable in at least one direction available from Culp, Inc. of High Point, N.C. in a number of fabric weights.
Layer 4: A cushion 200 as previously disclosed in relation to
Layer 5: Cotton tricot, stretchable in at least one direction available from Culp, Inc. of High Point, N.C. in a number of fabric weights.
Layer 6: A water-based adhesive commercially available under the product name SIMALFA® 309 from Alfa Adhesives, Inc. of Hawthorne, N.J., which is used to bond the cover to the assembly that includes Layers 1 through 5.
Cover: A standard quilted cover as well known in the mattress industry. Alternatively, a non-quilted stretch cover such as is common for memory foam beds such as TEMPUR-PEDIC® brand memory foam beds sold by Tempur-Pedic, Inc. of Lexington, Ky. Optionally, the cushion may also include elements of top layer 106 (for example a layer of foam in addition to the cotton tricot, the adhesive, and the cover) and bottom layer 108 (for example, a layer of foam in addition to the pocketed coil springs, the adhesive, and the cotton tricot).
As previously mentioned, the core structures of cushions of the invention may comprise (e.g., may be formed from) a gel. Gel core structures have a ‘feel’ that is desirable in many types of cushions such as mattresses, seat cushions, shoe insoles, and the like. Gel is able to buckle with more agility than relatively stiffer elastomers, and sometimes exhibit multiple curves in the load versus deflection plot during buckling. A relatively stiffer elastomer may simply fold and, thus, not exhibit a gradual buckling event, or may not buckle under typical cushioning pressures when manufactured at reasonable wall thicknesses. Gel also provides cushioning without buckling, due to its ability to flow and conform in shape around a cushioned object. Thus, if the cushioned object ‘bottoms out,’ the resultant pressure peak on the cushioned object may be less if the cushion comprises gel rather than a relatively harder elastomer. Although gels may be used in some embodiments, non-gel elastomers and/or higher-durometer elastomers, such as cross-linked latex rubber or cross-linked and non-cross-linked synthetic elastomers of many types (e.g., SANTOPRENE®, KRATON®, SEPTON®, isoprene, butadiene, silicone rubber, thermoset or thermoplastic polyurethane, etc.).
There are numerous types of gels that may be used to form core structures as described herein including plasticized silicone gels, plasticized polyurethane gels, plasticized acrylic gels, plasticized block copolymer elastomer gels, and others. Plasticized block copolymer gels may be relatively less tacky and less susceptible to bleed or wicking out of the plasticizer relative to some other types of gels. Plasticized block copolymer gels also may exhibit greater tensile, compression, shear and/or tear strengths relative to some other types of gels, and may not exhibit permanent deformation after being repeatedly stressed or stressed continuously for a long period of time under conditions to which cushions for cushioning at least a portion of a body of a person, body of an animal, or other thing may be subjected.
Three non-limiting examples of gels that may be used to form core structures as described herein are provided below.
A gel may be formed by melt blending SEPTON® 4055, which is a relatively high molecular weight Styrene-Ethylene-Ethylene-Propylene-Styrene (SEEPS) tri-block copolymer elastomer, with white paraffinic mineral oil with no or low aromatic content, such as Carnation Oil. The durometer of the gel can be adjusted as desirable (for example, to tailor the buckling pressure threshold for a given application) by adjusting the ratio of SEEPS to oil. A higher ratio will result in a higher durometer gel. By way of non-limiting example, in some embodiments, the gel may include between 150 and 800 parts by weight of mineral oil to 100 parts by weight SEPTON® 4055. In some embodiments, cushions such as mattresses and seat cushions may include between 250 and 500 parts by weight mineral oil to 100 parts by weight SEPTON® 4055.
The gel can also be stiffened by adding a stiffness reinforcer. For example, a filler material, such as microspheres, may be incorporated into the gel as described in U.S. Pat. No. 5,994,450, which has been incorporated herein by reference.
A gel may be formed by melt blending KRATON® E1830, which is a Styrene-Ethylene-Butylene-Styrene (SEBS) tri-block copolymer elastomer in which the EB midblocks of the copolymer molecules have a relatively wide range of relatively high molecular weights, with white paraffinic mineral oil with no or low aromatic content, such as Carnation Oil. As in Example 1, the durometer of the gel can be adjusted as desirable by adjusting the ratio of SEBS to oil. A higher ratio will result in a higher durometer gel. By way of non-limiting example, in some embodiments, the gel may include between 100 and 700 parts by weight of mineral oil to 100 parts by weight KRATON® E1830. In some embodiments, cushions such as mattresses and seat cushions may include between 150 and 450 parts by weight mineral oil to 100 parts by weight KRATON® E1830.
The gel can also be stiffened by adding a stiffness reinforcer. For example, a filler material, such as microspheres, may be incorporated into the gel as described in U.S. Patent Application Publication No. US 2006/0194925 A1, which published Aug. 31, 2006 and is entitled Gel with Wide Distribution of MW in Mid-Block,” which is incorporated herein in its entirety by this reference.
A gel may be formed by melt blending a mixture of KRATON® E1830 and SEPTON® 4055, with white paraffinic mineral oil with no or low aromatic content, such as Carnation Oil. As in Examples 1 and 2, the durometer of the gel can be adjusted as desirable by adjusting the ratio of the polymer mixture to oil. A higher ratio will result in a higher durometer gel. By way of non-limiting example, in some embodiments, the gel may include between 100 and 700 parts by weight of mineral oil to 100 parts by weight of the polymer mixture. Furthermore, the gel may be stiffened as described in relation to Examples 1 and 2.
In any of the examples provided above (or in any other embodiment of the invention), all or part of the plasticizer (e.g., mineral oil) may be replaced with a resin that is solid or liquid at a temperature at which a cushion including the gel is to be used, such as, for example, a hydrogenated pure monomer hydrocarbon resin sold under the product name REGALREZ® by Eastman Chemical Company of Kingsport, Tenn. Use of an ultra-viscous resin may cause the resultant gel to have a relatively slow rebound, which may be desirable for some cushioning applications. Many such resins are commercially available, and REGALREZ® is merely provided as a suitable, non-limiting example. Hollow glass or plastic microspheres may be added to these slow rebound gels to lower the density and/or to increase the durometer.
For example, if 1600 parts of REGALREZ® 1018 is used as the plasticizer with 100 parts of SEPTON® 4055, the resulting gel may be relatively soft and exhibit slow-rebound characteristics at room temperature. REGALREZ® 1018 is a highly viscous fluid at room temperature. Alternatively, in similar embodiments, REGALREZ® 1018 may be replaced with a mixture of mineral oil and any of the REGALREZ® products that are solid (usually sold in chip form) at room temperature. Such a slow-rebound gel that is plasticized using a blend of mineral oil and resin that is solid at room temperature may exhibit less temperature-related changes in durometer and rebound rate over temperatures comfortable to people than will a gel that includes REGALREZ® 1018 as a sole plasticizer, which has a viscosity that changes with temperature over the range of temperatures comfortable to people (e.g., temperatures near room temperature).
Slow-rebound gels that are plasticized with resin may be may be relatively tacky or sticky relative to other gels. In such cases, when the gel core structures buckle and one part of a core structure touches another part of the core structure, they may have a tendency to stick together and not release when the cushioned object is removed. In an effort to reduce or eliminate such occurrences, a surface of the gel core structures may be coated with a material that will stick to the gel, but that is not itself sticky. For example, a surface of the gel core structures may be coated with one or more of microspheres and Rayon (velvet) flocking fibers. For example, microspheres may adhere relatively well to the surface of gel core structures and not easily come off. Thus, the surface of the gel material may be rendered less tacky or un-tacky because the outer surface now comprises the outer surfaces of millions of non-tacky microspheres. As another example, tiny Rayon (velvet) flocking fibers also may adhere relatively well to the surface of the gel core structures and not easily come off. Thus, the surface of the gel material may be rendered less tacky or un-tacky because the outer surface now comprises the outer surface of thousands of non-tacky short fibers. A third example is to put a thin layer (e.g., skin) of polyurethane elastomer over the gel material, either by application of a thermoplastic polyurethane film, or by coating the gel in an aqueous dispersion of polyurethane and allowing it to dry, or by other methods.
Gel core structures made with a relatively slow-rebound elastomer may have a different feel than gel cores structures made with other gels that exhibit a relatively faster rebound rate. Such slow-rebound gel core structures may be used in conjunction with a top layer or bottom layer comprising a memory foam, since memory foam also exhibits relatively slow rebound rates.
Embodiments of core structures (e.g., gel core structures) as described herein above may be manufactured using any process that can create core structures of any desirable configuration and any desirable material composition. The following manufacturing methods are provided as non-limiting examples:
In embodiments in which the core structures comprise a thermoplastic material (e.g., a thermoplastic gel), they may be manufactured using an injection molding process. A mold is made by means known in the art with cavities that are filled by any standard injection molding process. The material is cooled within the mold cavity, the mold is opened, and the fabricated part is ejected from or pulled out of the mold. A gel material of a molded part may conform to ejector pins used to eject the molded part out from the mold cavity as the pins are thrust into the mold cavity to eject the part, such that the part may not be properly ejected from the mold cavity. Thus, the injection molds may not include such ejector pins, and the mold operator may manually pull out the molded gel products from the mold cavity. One advantage to injection molding gel core structures is that, when the molded gel core structures are pulled on by a mold operator, the Poisson's effect may temporarily significantly reduce the cross-sectional thickness of the molded gel core structures, and, as a result, the molded gel core structures may pull out from the mold cavity without the need for a draft angle on the cavity surfaces, and may even be removed if the mold cavity includes undercut regions in some cases. In embodiments that comprise a gel which when melted or before curing is sufficiently non-viscous to pour, the gel can be poured into the cavities in the mold, then allowed to cool (if the gel is a thermoplastic material) or to cure (if the gel is a thermoset material), then pulled from the mold.
In additional embodiments of the invention, core structures as described herein may be manufactured using an extrusion process. For example, each gel core structure of a cushion may be separately extruded using extrusion processes known in the art. For example, molten material may be forced through an aperture in a die using a rotating, stationary screw in a barrel (e.g., an extruder). The die aperture may have the desired cross-sectional shape of the core structure to be formed. The extruding material may be cut-off or severed at intervals corresponding to the desired lengths of the core structures, and the extruded core structures may be cooled. The core structures then may be arranged in a desired pattern for the cushion to be formed, and connected to the connecting layers (for example, being heat fused to the cotton tricot fabric connecting layers). The die used in such an extrusion process may be relatively small, as it may correspond in size to only a single core structure, which may be desirable relative to processes that require tooling having a size comparable to that of the entire cushion being formed. Thus, embodiments of core structures as disclosed herein may be manufactured using tooling and equipment that is relatively smaller, less complicated, and less expensive compared to tooling and equipment used to form previously known gel or buckling gel cushions.
In situations in which the equipment and/or tooling cost is not as important as other considerations, such as having an integral skin or where volume of production is such that the equipment and tooling cost is amortized over a very large number of parts and thus becomes inconsequential), an open-faced pressure-screeding system make be used to manufacture core structures in accordance with additional embodiments of the present invention. Such methods are disclosed in, for example, U.S. Pat. No. 7,666,341, which issued Feb. 23, 2010 to Pearce, and which is incorporated herein in its entirety by this reference. Such a process is briefly disclosed below.
A screed mold may be formed or otherwise obtained that has a rigid body. The screed mold comprises an open face mold, and has multiple cavities (recesses) in the rigid body that define cavities of the screed mold, such that gel or another material may be forced into the cavities of the mold to form core structures of a desirable shape. The screed mold optionally may have a raised lip around a periphery of the mold, which allows for a sheet of gel or other material to form at the top of the screed mold over the face, which sheet will be integral with the core structures formed in the cavities of the mold. In additional embodiments, the screed mold may not include such a raised lip, such that the gel or other material may be screeded flush or nearly flush with the top surface of the open face of the mold by a screed head used to inject the gel or other material into the cavities, or by another tool, with any excess being scraped off after that portion of the mold exits the screed head or other tool.
An injection head then may be used to inject gel or other material into the mold cavities. The injection head may have a plurality of distribution channels therein through which molten gel or other material may flow. The distribution channels optionally may be subdivided into sub-distribution channels, and the distribution or sub-distribution channels may terminate at exit ports through which molten gel exits the injection head and enters the cavities in the screed mold. The injection head also may include at least one external or internal heating element for heating the injection head.
The injection head may be positioned adjacent the screed mold in a location and orientation such that molten gel may flow from the injection head distribution channels out of the exit ports and into the cavities of the screed mold and, optionally, into a skin-forming recess of the mold.
A pumping source may be utilized to pressurize and pump the molten gel or other material and force it into the injection head, through the distribution channels of the injection head, out of the exit ports of the injection head, and into the screed mold. Relative movement may be provided between the injection head and the screed mold during the injection process, such that the injection head fills the mold cavities and screeds molten gel or other material off from the open face of the mold in a progressive manner.
The gel or other material may be cooled and solidified within the cavities of the mold, after which the molded gel or other material may be removed from the cavities of the screed mold. Thus, core structures having a desired geometric shape may be formed, and may be formed with or without an integral skin layer.
An integral skin layer may allow the molded structure comprising a plurality of core structures to be lifted out from the mold in a single piece, since they are all connected by the skin layer. Additionally, the integral skin layer may maintain the core structures properly positioned relative to one another. However, if no integral skin layer is desired, the screed mold side lips may be omitted and the screed mold may be automatically or manually scraped off at the top of each core structure during or after the molding process. Then, to avoid the necessity of removing each member individually, a fabric may be pressed into the molten gel or other material. If the material has solidified within the mold, end portions of the core structures may be heated to a temperature sufficient to re-melt the end portions of the core structures prior to pressing the fabric into the end portions of the core structures. The core structures then may be cooled, and the assembly comprising the fabric and the core structures attached thereto may be pulled out of the mold. Other methods may also be used to aid in removal of core structures from the mold cavities together, or each core structure may simply be individually pulled out from the mold.
In additional embodiments, a partial skin layer may be integrally formed over one or both sides of the core structures to connect the core members together, but to improve the breathability of the resulting cushion. This may be done by, for example, configuring an open-faced screed mold with areas which, when screeded and/or scraped, form holes through the skin without removing the entire skin. The holes can be between core structures or located over an interior space of a hollow core structure.
The joiner ribs may be coupled to the core structures using any method known in the art. For example, the joiner ribs may be glued, heat fused, or otherwise adhered to the core structures. In additional embodiments of the invention, joiner ribs may be integrally formed with the core structures such that an entire row or line of core structures may be pulled out from the mold together.
If desired, a fabric may be fused into the tops and/or bottoms of the core structures, as described above. When joiner ribs are used, it may be easier and require less labor to locate a joined line of core structures into a heat fusing fixture than to locate each of a plurality of un-joined core structures into such a fixture. Fabric may be fused into the ends of core structures by placing the core structures in their desired spacing and orientation, then placing the fabric over the top and smoothing out any wrinkles in the fabric. A heated platen then may be brought into contact with the fabric and the underlying ends of the core structures. The temperature of the heated platen may be such that the gel or other material will melt, but not burn or otherwise degrade. The heated platen may be part of a press device, which may have a mechanical stop at a predetermined distance below the plane at the top of the fabric. For example, the heated platen may be stopped at a predetermined distance below the plane at the top of the fabric upon closing the press that is at least half the thickness of the fabric. After a period of time sufficient to melt the gel or other material, and to allow the gel to flow into the external and/or internal interstices of the fabric, the platen may be raised, and the gel or other material may be allowed to cool and solidify. The assembly then may be removed from the press. In additional embodiments, core structures may be oriented between two pieces of fabric, and the assembly may be pulled through a pair of opposing heated platens to simultaneously fuse the top and bottom fabrics to the tops and bottoms of the core structures, respectively. Such a process may be continuously operated. The fabric may be supplied by rolls of the fabric, and the core structures may be placed between the fabrics continuously.
Embodiments of cushions of the present invention may include a cover, which may be bonded or unbonded to the interior cushioning member of the cushion. For example, a cover may simply be slipped over the interior cushioning member, and, optionally, may be closed using, for example, a zipper or hook-and-loop material. In embodiments of furniture cushions, the cover may comprise an upholstery fabric, leather, etc. In embodiments of wheelchair cushions, the cover may comprise a stretchable, breathable, waterproof fabric, such as a spandex-type knitted material laminated to a thin polyurethane film.
Any of the cushions shown in
Embodiments of core structures as described herein may be used in an unlimited number of cushioning applications. Core structures may be designed to buckle at a predetermined threshold pressure level, and this buckling may relieve pressure hot spots and redistribute pressure so that no part of the cushioned object receives pressure substantively above the predetermined threshold pressure level. In addition, the ability of the individual core structures to deform laterally relative to the direction of the principal cushioning load may relieve shear stresses on the cushioned object. Further, the nature of most elastomers and especially plasticized elastomers such as gel, is to absorb shock and attenuate vibration, which, when combined with the shock absorption and vibration attenuation that is provided by buckling action of core structure, may provide further improved shock absorption and vibration attenuation characteristics in accordance with some embodiments of cushions of the invention. Any cushioning application needing any or all of these characteristics may benefit by utilizing core structures connected as described herein. It would be impossible to list all such cushioning applications; however, a few applications include consumer and medical mattresses, consumer and medical mattress overlays, pillows for the head, seat cushions, neck cushions, knee pads, shoe insoles, shoe sock liners, shoe midsoles, shoe outsoles, orthopedic braces, wheelchair positioners and cushions, surgical positioners, heel pressure relievers for invalids, crib mattresses, crib pads, diaper changing pads, pet beds, pet pads, bicycle seats, bicycle seat overlays, seat overlays or seats for cars, motorcycles, recreational vehicles (RVs,) semi-trucks, heavy equipment and farm tractors, gymnastic pads, yoga pads, aerobic pads, exercise benches, boxing gloves, sports impact padding, helmets, aircraft seats, furniture for the home including sofas, recliners, love seats and chairs, furniture for the office including office chairs, patio furniture, hunting pads, baby carrier straps, infant car seats, backpack straps, backpack scapula pads and backpack and fanny pack waste bands.
The word “unitary” when used to describe the support structure herein can mean a single structure or can mean a structure made by joining (for example, by adhesively joining polyurethane foam or latex foam rubber) originally separate pieces.
Additional non-limiting examples of embodiments are set forth below.
A cushion, comprising: a plurality of core structures, each core structure of the plurality of core structures comprising a deformable polymer material, each core structure of the plurality of core structures configured as a column having a column axis; wherein each core structure of the plurality of core structures is interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures.
The cushion of Embodiment 1, wherein each core structure of the plurality of core structures is interconnected along a length thereof to at least one other core structure of the plurality of core structures by a joiner rib extending along at least a portion of a length of each core structure of the plurality of core structures.
The cushion of any one of Embodiments 2, wherein the joiner rib is integrally formed with each core structure of the plurality of core structures.
The cushion of any one of Embodiments 2 and 3, wherein the joiner rib extends along the entire length of each core structure of the plurality of core structures.
The cushion of any one of Embodiments 2 and 3, wherein the joiner rib extends along a middle portion of the length of each core structure of the plurality of core structures.
The cushion of any one of Embodiments 2 through 5, wherein the joiner rib comprises the deformable polymer material of each core structure of the plurality of core structures.
The cushion of any one of Embodiments 2 through 6, wherein each core structure comprises a first joiner rib extending along at least a portion of a length of the core structure on a first side of the core structure; and a second joiner rib extending along at least a portion of the length of the core structure on an opposite second side of the core structures.
The cushion of any one of Embodiments 1 through 7, wherein the plurality of core structures comprises a plurality of lines of interconnected core structures, the core structures in each line of interconnected core structures being interconnected to at least one other core structure in the line of interconnected core structures.
The cushion of any one of Embodiments 1 through 8, wherein each core structure of the plurality of core structures is configured to buckle when compressed along the column axis of the core structure to a pressure beyond a threshold pressure level.
The cushion of any one of Embodiments 1 through 9, wherein the deformable polymer material comprises gel.
The cushion of any one of Embodiments 1 through 10, wherein the core structures of the plurality of core structures are oriented generally parallel to one another, and the column axes of the core structures of the plurality of core structures are oriented generally perpendicular to a cushioning surface of the cushion.
The cushion of any one of Embodiments 1 through 11, wherein at least one of top ends and bottom ends of the core structures of the plurality of core structures are interconnected by at least one of fabric and a skin layer.
A cushion comprising: a plurality of core structures, each core structure of the plurality of core structures comprising a gel material, each core structure of the plurality of core structures configured as a column having a column axis, each core structure of the plurality of core structures being interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures by at least one joiner rib; wherein each core structure of the plurality of core structures is configured to buckle when compressed along the column axis of the core structure to a pressure beyond a threshold pressure level.
The cushion of Embodiment 13, wherein the at least one joiner rib is integrally formed with each core structure of the plurality of core structures.
The cushion of any one of Embodiments 13 and 14, wherein the plurality of core structures comprises a plurality of lines of interconnected core structures, the core structures in each line of interconnected core structures being interconnected to at least one other core structure in the line of interconnected core structures by the at least one joiner rib.
The cushion of Embodiment 15, wherein the core structures in each line of interconnected core structures are staggered.
The cushion of any one of Embodiments 13 through 16, wherein the at least one joiner rib comprises: a first joiner rib extending along at least a portion of a length of a first core structure of the plurality of core structures on a first side of the core structure, the first joiner rib connecting the first core structure to a second core structure of the plurality of core structures; and a second joiner rib extending along at least a portion of the length of the first core structure on an opposite second side of the first core structure, the second joiner rib connecting the first core structure to a third core structure of the plurality of core structures.
The cushion of any one of Embodiments 13 through 17, wherein the axes of the core structures of the plurality of core structures are oriented generally parallel to one another, and the column axes of the core structures of the plurality of core structures are oriented perpendicular to a cushioning surface of the cushion.
The cushion of any one of Embodiments 13 through 18, wherein the at least one joiner rib extends between core structures of the plurality of core structures in a direction is orientated generally parallel with the cushioning surface.
A method of forming a cushion, comprising: forming a plurality of core structures each comprising a deformable polymer material and configured as a column having a column axis; and configuring each core structure of the plurality of core structures to be interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures by a joiner rib.
The method of Embodiment 20, wherein configuring each core structure of the plurality of core structures to be interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures comprises configuring each core structure of the plurality of core structures to be integrally interconnected along at least a portion of a length thereof to at least one other core structure of the plurality of core structures by an integral joiner rib.
The method of Embodiment 21, further comprising: orienting the axes of the core structures of the plurality of core structures generally parallel to one another; and orienting the column axes of the core structures of the plurality of core structures perpendicular to a cushioning surface of the cushion.
The method of any one of Embodiments 21 and 21, further comprising integrally forming the joiner rib with at least two core structures of the plurality of core structures.
The method of any one of Embodiments 21 through 22, further comprising forming the plurality of core structures to comprise a plurality of lines of interconnected core structures by interconnecting the core structures in each line of interconnected core structures to at least one other core structure in the line of interconnected core structures with the integral joiner rib.
The method of any one of Embodiments 20 through 23, further comprising configuring each core structure of the plurality of core structures to buckle when compressed along a column axis of the core structure to a pressure beyond a threshold pressure level.
The method of any one of Embodiments 20 through 24, further comprising selecting the deformable polymer material to comprise gel.
The method of any one of Embodiments 20 through 25, further comprising interconnecting at least one of top ends and bottom ends of the core structures of the plurality of core structures using at least one of fabric and a skin layer.
Embodiments of the invention may be susceptible to various modifications and alternative forms. Specific embodiments have been shown in the drawings and described in detail herein to provide illustrative examples of embodiments of the invention. However, the invention is not limited to the particular forms disclosed herein. Rather, embodiments of the invention may include all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the following appended claims. Furthermore, elements and features described herein in relation to some embodiments may be implemented in other embodiments of the invention, and may be combined with elements and features described herein in relation to other embodiments to provide yet further embodiments of the invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/216,787, which was filed on May 21, 2009 and entitled “Cushions with Individually Pocketed Non-Linear Members, Gel Springs with Joiner ribs, Gel Cores,” which is incorporated herein in its entirety by this reference. This application is a continuation-in-part of U.S. patent application Ser. No. 12/287,047, which was filed on Oct. 3, 2008 and entitled “Gel Springs,” which is also incorporated herein in its entirety by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 61216787 | May 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12287047 | Oct 2008 | US |
| Child | 12784381 | US |
